code: def test_check_connection(self, handler):
      res = handler.check_connection()
      assert res.success, res.error_message
  
file_path: mindsdb/tests/handler_tests/test_postgres_handler.py
imports: import time
  import pytest
  import docker
  from mindsdb.integrations.handlers.postgres_handler.postgres_handler import PostgresHandler
  from mindsdb.api.executor.data_types.response_type import RESPONSE_TYPE
label_desc: Use image node_id 2 for calling the TestPostgresHandler obj's underlying member method code with example usage: obj.test_check_connection(handler) without return types